Wat betekent: "Use of $this in global code might be unatended PHP (PHP0437)"?

[pjdevries]

Van René Kreijveld:

Mijn code editor meldt vaak de volgende error:
Use of $this in global code might be unatendedPHP(PHP0437)
Ik heb er geen last van, de code werkt gewoon. Waar ik dit bijvoorbeeld veel zie is in een tmpl file van een view. Daar wordt veel $this gebruikt, bijvoorbeeld:
$wa = $this->document->getWebAssetManager();

[HermanPeeren]

$this is the View in which the tmpl-file should be included (todo: where and how is that done in Joomla).
In PHP8.0 this kind of referring to a variable that is not defined in the file itself but in a more global scope gets a warning.

You probably should put a @var in a docblock to tell the code analyser what $this is, like this for the article-view in the backend:

/**
 * @var Joomla\Component\Content\Administrator\View\Article\HtmlView $this
*/

Todo: test this, I was just typing this, without first trying it out.

See: https://stackoverflow.com/questions/76934253/how-to-solve-warning-use-of-this-in-global-code-might-be-unatendedphpphp0437 (for CodeIgniter, but same problem).